MONTHLY LETTER OF THE-BUREAU OF ENTOMOLOGY 
UNITED STATES DEPARTMENT OF AGRICULTURE 
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Number 122 
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SWMEE staesoeremnecees: tect ee eee es ee ee ts re eer et beens Se eee ese 
June, 1924 

J. E. GRAF APPOINTED ENTOMOLOGIST IN CHARGE OF 
TRUCK-CROP INSECT INVESTIGATIONS 
J. E. Graf, for many years in charge of field operations in connection 
with Truck Crop Insect Investigations in the Bureau of Entomology, ana for 
some months Entomologist Acting in Charge of these investigations, has been 
selected as head of the division, effective June 1, 1924. 
FOREST INSECT INVESTIGATIONS 
F, C. Craighead, Entomologist in Charge. 
Dr. F. C. Craighead left Washington on June 19 for an extensive trip 
to inspect the work at the various Forest Insect field stations, and also 
the cooperative work being conducted at the Forest Service experiment stations; 
both the Kaibab Project in Utah and the Southern Oregon-Northern California 
Project, the largest barkbeetle control projects ever instituted by the 
Government, will be inspected. 
J. M. Miller reports that an insect survey of the cutover areas of the 
Sierra National Forest in California was completed during May by Mr. Person 
and Mr. Wagner. The results are of considerable importance, as the survey 
uncovered a definite relation between insect losses and the marking practice 
employed on National Forest timber sales. Altogether, six sale areas covering 
2,680 acres were cruised as a basis. The marking policy employed on these 
sales has been to leave from 25 per cent to 50 per cent of the merchantable 
timber on the area for further increment and to shorten to from 50 to 75 years 
the period in which a second cutting can be made. It was found that insect 
losses were not only exceeding the annual increment on some of the areas but 
were rapidly depleting as well the timber capital that had been reserved. In 
all cases this loss was caused by an ENDEMIC barkbeetle infestation. The 
reason back of this condition seems to be that the removal of from 50 per cent 
to 75 per cent of the original stand by logging does not reduce the amount 
of barkbeetle loss on an area. The loss of 15 trees per section in a fully 
stocked stand is not considered serious, but the loss of 15 trees per section 
on a cutover area may mean the loss of a relatively high per cent of the timber 
left for increment and second cutting. The situation apparently calls for a 
remedy which will have to be worked out either through clear cutting of all 
merchantable timber or the elimination of the insect loss through direct control 
methods. 
Mr. Miller is to give a talk at the joint meeting of the Society of 
American Foresters and the Ecological Society which will be held at Stanford 
University June 25 to 28. He will emphasize the need of through cooperation 
